In recent years, wireless communication devices, such as cellular phones, notebook computers, access point and the like are more popular with the development of science and technology. The antennas with simple structure have become increasingly popular, especially ones of which antennas operate based on the principle of inverted-F antenna.
In general, PIFA operates with the outer conductor and inner conductor of the coaxial cable to be connected to the grounding end and the signal feeding end of PIFA to transmit signals by the radiating element of PIFA. Of course, it may not use the coaxial cable and may be replaced by other grounding elements and signal transmitting units. However, the shape, the structure and the size may affect the operating frequency and matching impedance of the antenna, and the needs toward antennas may be different from a variety of devices where the antennas are disposed. Therefore, in this technical field, the engineers devote to improve the structure of the antenna constantly in order to have the best performance, reduce the occupying space and meet market demand.
Therefore, it is tried to rectify those drawbacks and provide an antenna that has a simpler structure and is more adjustable for matching impedance to integrate two bandwidths. The present invention provides a dual-band antenna in order to achieve the foresaid objective.